Hydraulic speed and temperature governing system



g- 10, 1965 T. F. CRAMER 3,199,522

HYDRAULIC SPEED AND TEMPERATURE GOVERNING SYSTEM Filed Jan. 16, 1961 2 Sheets-Sheet l FlG.l.

FIG.2.

INVENTOR. THOMAS F. CRAMER BY Wane W ATTORNEYS Aug. 10, 1965 T. F. CRAMER HYDRAULIC SPEED AND TEMPERATURE GOVERNING SYSTEM Filed Jan. 16, 1961 2 Sheets-Sheet 2' FIG.5.

INVENTOR. THQMAZ's ECRAMER TTORNEYS' United States Patent 318 9522 HYDRAULIC SPEED AND TEMEERATURE GGJERNZNG SYS'i-EM Thomas F. Cramer, Stratford, Guthrie, Canada, assignor to Holley Carburetor Company, Warren, Mich, a corporation of Michigan Filed .lan. 16, 1961, Ser. No. 82,367 12 Claims. (Cl. 137-2il) Temperature of the hydraulic fluid results in a number of problems in hydraulic governors. If the governor calibration is made with hydraulic fluid at temperatures above 200 degrees F., early governor cutoff is experienced at lower temperatures, e.g., about 150 degrees F. If the governor calibration is made with hydraulic fluid at temperatures about 150 degrees F then at elevated temperatures above 200 degrees F., the low load speed is higher than desirable. In order to improve the governing regulation and prevent premature pressure build-up in the system, a temperature control is provided for reducing fluid pressure at low fluid temperature, thus eliminating early cutoff.

It is an object of the presentinvention to provide a hydraulic governing system which includes temperature compensating control means for correcting errors of speed introduced into the system by the eflect of the temperature of the fluid on its viscosity.

It is another object of the present invention to provide a hydraulic engine speed control system including temperature control valve means in the system for compensating for an early pressure build-up in the system due to the effect of the temperature of the fluid on its viscosity, thus eliminating early governing cutolf in the system.

Still another object is to provide a hydraulic governor which is simple in construction, economical to manufacture and efilcient in operation.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings illustrating a preferred embodimentof the invention, wherein:

FIGURE 1 is an elevational view showing the connection of the speed responsive valve unit to a throttle control motor mounted on a carburetor of an internal combustion engine.

FIGURE 2 is a sectional elevational view of the rotatable valve structure.

FZGURE 3 is a diagrammatic representation showing in particular how an end of the bi-metallic spring is connected to the valve element.

FIGURE 4 is a-fragmentary view, in section, showing the valve in a partially closed position.

FEGURE 5 is a fragmentary view, in section, showing the valve in a completely open position.

FIGURE 6 is an'elevational view, in section, showing a modified speed responsive control valve unit which has a combined reservoir, pump, speed responsive valve, and temperature compensating control valve.

FIGURE 7 is a sectional view taken on the line 7-7 of FIGURE 6.

Referring now to FIGURE 1, there is shown a speed control system for an internal combustion engine which includes a carburetor 155 having primary and secondary barrels, the inlet to the primary barrel being indicated at 12, this barrel having a throttle therein, the position of which is more or less diagrammatically illustrated at 14.

Connected to the throttle 14 is a diaphragm type ofl1ydraulic motor 16. The motor 16 includes an actuating chamber which is connected by an external conduit or passage 18 to a speed responsive unit 29, details of which will be subsequently described. Upon admission of hydraulic fluid under pressure to the actuating chamber, not shown, the chamber expands, moving the flexible diaphragm, not shown, thus imparting rotation through suitable means, not shown, to the throttle 14 which results in closing movement thereof. The throttle 14 which is thus controlled by the motor 16 is the same throttle as controlled by the usual accelerator pedal. The manual and automatic controls of the throttle are coordinated by conventional means well known in the art.

The system includes an external positive displacement pump 22 which may, if desired, be a rotary gear pump which has a pressure regulating valve, not shown, directly associated therewith. The pump 22 is adapted to circulate hydraulic fluid, as an example the engine lubricating oil, throughout the speed control system. The speed responsive unit 2% is provided with an internal supply passage 24, to one part of which is connected a conduit 26 which is located externally of the unit 20. Conduit 26 connects the supply passage 24 with a passage 23 provided at one side of the unit 20. A pressure metering orifice 30 is provided in the passage 28 through which hydraulic fluid from the positive displacement pump 22 is delivered through conduit 26 to the supply passage 24. One end of the supply passage 24 is connected by the external passage or conduit 18 to the motor 16 in the manner previously described.

A temperature compensating control valve 25 is incorporated in the conduit 26 for correcting errors of speed introduced in the system by the effect of the temperature of the fluid on its viscosity as will be explained in detail later on in the specification.

Inasmuch as the fluid suppliedby the pump 22 may be at a substantially greater pressure than necessary in the supply passage 24 for the operations to be performed by the motor 16, itis desirable to provide a means for limiting maximum pressure of hydraulic fluid supplied to the motor 16. This means comprises a pressure relief valve in the form of a ball valve 32 urged by a compression spring 34 against the valve seat 35. The spring 34 is maintained under a predetermined pressure by an adjustable spring seat 38 and when the predetermined pressure is exceeded, fluid pressure moves-the ball 32 off its seat 36 and permits fluid to exhaust, as an example to a sump, reservoir or the crankcase of an engine, through a passage 40 which communicates with a chamber 42 and exhaust opening in the unit 20.

Extending into the interior of the unit 20 is a rotary drive shaft 44 having an external portion 46 coupled to an external driver 48. The driver 48 may be driven at a speed directly proportional to engine speed or directly proportional to roadspeed of the vehicle.

The inner end of the shaft 44 is provided with a longitudinally extending bypass passage 50 which communicates with thesupply passage 24. Intermediate the-ends of the shaft 44 there is provided a transverse opening communieating with the passage 50 which receives an elongated spinner 52 illustrated as comprising a pair of diametrically opposite extending arms. The spinner 52 has a longitudinally extending passage 54 provided. therein closed at one end by a plug 56. Adjacent the other end of the spinner 52, the passage 54 communicates with a transverse passage 5$ forming a governing metering port. The last mentioned end of the spinnii52 is threaded as indicated at 66 and receives an adjustable nut 62 constituting a seat for a compression spring 64. Slidable on the spinner 52 is a sleeve valve 66 urged to the left as seen in FIGURE 1 by the compression spring 64 but movable radially outwardly under the influence of centrifugal force. Thus, at a predetermined rotational speed of the shaft 44, the sleeve valve 66 commences to close the port 58 and meter the flow therethrough as will be subsequently described.

During operation of the engine, of which the carburetor It) is a part (and without considering the effect of the viscosity of the fluid on the operationof the speed control system), below the predetermined speed (either engine speed or road speed), hydraulic fluid such as oil under the pressure delivered by the pump 22 enters the supply passage 24. At this time, the sleeve valve 66 is in an open position, as shown in FIGURE 1, permitting the hydraulic fluid to flow through the conduit 26 into passages 50 and 54, the port 58 to the chamber 42 provided in the unit 20 from which. the fluid flows through a suitable fitting received in the threaded opening 70 to exhaust such, for example, as the crankcase of the engine. However, when the speed of the shaft 44 arrives at the lower limit of the governed speed, the valve sleeve 66 starts to close the valve port 58 and accordingly, pressure within the unit 20 builds up to a point determined by the strength of the spring 34. This pressure is transmitted to the motor 16 through the conduit 18 to move the throttle 14 in a closing direction.

It has been found that when the system operates in the manner just described, the fluidity of the hydraulic fluid becomes a factor. It the hydraulic fluid, such as the engine lubricating oil, has a high viscosity, due to a low fluid temperature, each incremental movement of the speed responsive valve 66 across the port 58 produces pressure drops across the metering port 58 and metering orifice which difler from such pressure drops when viscosity is low. It has been found that with cold, high viscosity oil, the throttle motor 16 moves toward a closed position before the attainment of the desired governed speed. On the other hand, if the hydraulic fluid has a lower viscosity due to a higher fluid temperature, movement of the throttle 14 is initiated at a higher speed.

In order to compensate for or correct the errors of speed introduced-into the system by the effect of the temperature of the fluid on its viscosity, the temperature operated control valve 25 has been incorporated in the conduit 26 in series with the metering orifice 30 and the metering port 58 provided in the bypass passages 50 and 54. The valve 25 is normally partially closed, as shown in FIGURE 4, when the hydraulic fluid has a high viscosity to create a pressure drop across the valve 25 which is in series with the metering port 58 and metering orifice 30 to prevent pressure buildup.

More specifically, the valve 25 consists of a rotatable valve element 72 which is mounted in the valve housing 74. The valve housing 74 includes an inlet port 76 adjacent to and communicating with the spring chamber 73. A passage 80 connects the spring chamber 78 to the outlet port 82. The valve element 72 includes a radial passage 84, as best illustrated in FIGURES 4 and 5, which is adapted to open or restrict fluid communication through the passage 80. The end of the rotatable valve element 72 extending into the spring chamber 78 has a slot 85 therein which is adapted to receive and to retain the end 86 of the temperature responsive bi-metallic coil spring 38. This is best illustrated in FIGURE 3. The other end 87 of the bi-metallic spring 88 is connected to the housing 74 by suitable means, not shown.

When the speed responsive valve 66 initially starts to close and the hydraulic fluid is highly viscous (at a low temperature), pressure drops occur across the series of restrictions including the metering orifice 30, metering port 58 and the temperature compensating control valve 25 to maintain the pressure in the supply passage 24 at a pressure below the governing pressure required to actuate the throttle motor 16 at the predetermined speed.

As the temperature of the fluid increases, the valve 25 becomes less restrictive so that when the fluid attains a predetermined fluidity dependent on the temperature of the fluid, the valve will be in a fully open position as shown in FIGURE 5. This is accomplished by the expansion or contraction of the bi-metallic spring 38, depending, of course, on how it is initially placed in the housing '74 which in turn rotates the valve element 72 toward the fully open position shown in FIGURE 5. Stop means, not shown, are provided for limiting the rotation of the valve element 72 in the aforesaid opening direction to insure that the valve element 72 does not rotate past the completely open position and start to close. When the oil cools, the bi-metallic spring 83 is affected thereby so as to rotate the valve element 72 in the closing direction.

The embodiment of the speed responsive unit 20, shown in FIGURE 1, is substantially the same as the unit 96 shown in FIGURE 6 with the exception that the fluid pressure is supplied to the unit 90 by an internal pump rather than an external pump. In addition, the temperature responsive control valve 125 is incorporated in the unit 99. In such a case, the hydraulic fluid actuating the motor 16 is contained in a closed system including only the motor 16, the unit 90 and the conduit extending therebetween. Unit 90 includes its own reservoir or sump.

The unit 9t) comprises an integral hydraulic fluid reservoir, pump, relief valve, speed responsive control valve and temperature responsive control valve. More specifically, the unit 913 comprises a reservoir portion 92 in which is located a pump casing 94 which has an inlet port 96. Within the pump casing is a gear pump comprising the pump gears 98 and 100. The pump gear 100 is fixed to a drive shaft 102 which is driven by an external driver which may be rotated at a speed corresponding to engine speed or at a speed corresponding to the road speed of the vehicle.

Formed within the pump casing is an outlet passage 104 controlled by a pressure regulating relief valve 106 urged against its seat by an adjustable compression spring 108. The outlet or delivery passage 164 of the pump communicates with a passage 110 having a base pressure metering orifice 112 therein, the aforesaid passage 11% leading to and communicating with the vertically extending passage 114 provided at the lower end of the shaft 102.

The shaft 102 is rotatable in a bushing 116. The passage 114 has at the inner end thereof radially extending passages 11?; which are in fluid communication with an annular fluid chamber provided in the bushing 116. The chamber120 has a passage 124 leading therefrom which is in communication with the passage 126 provided in the housing of the unit 90. The passage 126 leads into a spring chamber 128 which forms a part of the temperature compensating control unit 125. The chamber 128 has an outlet passage 130 leading therefrom which is adapted to communicate with an annular chamber 132 provided in the bushing 116. The upper end of the shaft 102 includes a vertically extending passage 134- which has a pair of radially extending passages 136 in communication with the chamber 132 provided in the bushing 116.

The temperature compensating control valve is incorporated in the passage for correcting errors of speed introduced into the system by the effect of the temperature of the fluid on its viscosity. The temperature control valve 125 is similar in construction and operation to the temperature control valve 25 disclosed and described previously with the exception that the valve housing is integrally formed with the housing of the unit 90. The control valve 125 includes the valve element 127 and a bi-metallic coil spring 129 which is adapted to rotate valve element 127 from a restrictive position in passage 130 towards a completely open position upon changes in fluid viscosity.

The passage 134 communicates at its upper end, with the interior passage 136 of the spinner 140 closed at one end as indicated at 142 and having a metering port 144 adjacent its other end. Also adjacent the other end of the spinner 140 is an adjustable spring seat 143 on which is mounted a coiled compression spring 145 which, at its one end, engages a centrifugal speed responsive valve element 146 adapted under the influence of centrifugal force to compress the spring 145 and move to a position in which it closes the metering port 144. The annular chamber 132 is also in communication with a passage 148 leading to a port 150 which is adapted to be connected by a suitable conduit to the fluid throttle motor.

With the construction as described, operation of the internal combustion engine to which the shaft 102 is connected results in operation of the pump including gears 98 and 100, the gear 100 being directly driven by the shaft 102. This results in pumping hydraulic fluid from the reservoir 92 to the passage 104, excess fluid escaping through the relief valve 106 so that pressure in the passage 164 is maintained at a predetermined value. This permits the useof' a positive acting gear pump, while at the same time, the throttle motor and associated structure may be of relatively light construction consistent .with the operation of adjusting the throttle plate under relatively small hydraulic pressures.

During operation of the governor system, hydraulic fluid under the pressure as determined by cooperative action of the relief valve 106 and restriction 112, or at a lower pressure during initial operation, passes through the passages 110 and 114 into the spring chamber 128 from where the fluid passes into the variable restrictive passage 130 as determined by the valve element 127 and into the central passage 136 of the spinner 140. Initially, at speeds below the governed speed, the fluid escapes through the metering port 144 whence it may return to the reservoir 92 through a passage 152.

When the speed of the shaft 102 arrives near the lower limit of the governed speed, the valve 146 starts to close the port 144. At this point, as previously explained, the fluidity of the oil becomes a factor, If the oil has a high viscosity due to a low fluid temperature, each incremental movement of the speed responsive valve 146 across the port 144 produces pressure drops across the metering port 144 and the metering orifice 112 which differ from such pressure drops when the viscosity of the oil is low. As a result, the pressure prematurely builds up in the supply passage 148 before the exact cutoff speed is reached. The temperature responsive control valve 125 is incorporated in the system in series with the metering orifice 112 and the metering port 144.

so that a pressure drop will also occur across valve 125 when the oil is highly viscous to maintain the pressure in the passage 143 at a pressure below the governing pressure required to actuate the throttie motor 16 at the predetermined cutoff speed. The operation just described is identical with the operation of the system described for FIGURE 1.

The drawings and the foregoing specification constitute a description of the improved hydraulic governor in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

l. A hydraulic speed and temperature responsive control system interposed between a source of hydraulic fluid having its viscosity variable in accordance with temperature and the work for supplying hydraulic fluid to the work at a pressure not to exceed a predetermined value comprising a speed responsive device having a housing provided with a hollow interior, a substantially horizontal rigid barrier spanning the interior of said housing and dividing said housing into upper and lower compartments, means defining a fluid supply passage, a rotary tubular drive shaft mounted in the interior of 6 said housing and having one end extending outwardly from said housing beyond the top wall thereof which is adapted to be coupled to an external driver whose speed is to be sensed, said drive shaft including portions which extend through said upper compartment and said rigid barrier, means defining a first bypass passage which connects said supply passage with a reservoir, a pressure controlling relief valve in said first bypass passage, said drive shaft having an axially extending first passage therein, which intersects said supply passage, a cross opening in the portion of said drive shaft in said upper compartment, an elongated tubular cross shaft in said upper compartment fixed in said cross'opening in sealing relationship therewith, said cross shaft having a second passage therein, a first port in said cross shaft connecting said first and second passages, a second port in said cross shaft near one end thereof and opening into said upper compartment, a tubular speed responsive valve 'slidable over said cross shaft adjacent said second port, said second port, when open, providing an effective means for preventing an increase of pressure of fluid in said supply passage below a predetermined speed, said valve being movable by centrifugal force radially of said shaft across said second port to close said second port and thereby increase the fluid pressure in said supply passage to a pressure limited by said relief valve, and a temperature responsive control valve interconnected in said supply passage in series with said speed responsive valve to form a restriction variable in accordance with the temperature of the hydraulic fluid for compensating for the effect of the temperature of the fluid on its viscosity.

2. The hydraulic speed and temperature responsive control system defined in claiml wherein said temperature responsive control valve is mounted in said housing directly in said supply passage at a point upstream from said speed responsive valve.

3. The hydraulic speed and temperature responsive control system defined in claim 1 wherein said temperature responsive control valve is separate from said housing, and conduit means connecting said control valve with said supply passage.

4. The hydraulic speed and temperature responsive control system defined in claim 1 in which said one end of the cross shaft is provided with an adjustable spring seat and resilient means are provided between said seat and said valve for holding said valve away from said said second port until the predetermined speed has been attained.

5. The hydraulic speed and temperature responsive control system defined in claim 1 in which said bypass passage is located in said barrier and connects said supply passage with said upper compartment.

6. A hydraulic speed and temperature responsive control system for supplying hydraulic fluid having its viscosity variable in accordance with temperature at a pressure not to exceed a predetermined value, comprising a speed responsive device having a housing provided with a hollow interior, a substantially horizontal rigid barrier spanning the interior of said housing and dividing said housing into upper and lower compartments, said lower compartment serving as a fluid reservoir, a pump including a pair of pumping elements mounted in said reservoir, the inlet side of said pump being in direct communication with the fluid in the reservoir, a rotary tubular drive shaft mounted in the interior of said housing and havin one end extending outwardly from said housing beyond the top wall thereof which is adapted to be coupled to an external driver whose speed is to be sensed, said drive shaft including portions which extend through said upper compartment and said rigid barrier and having the other end connected to one of the pumping elements of said pump for actuating said pump, a supply passage in said drive shaft and said barrier connecting the discharge side of said pump with an outlet connection in said housing, means in said lower compartment defining a bypass passage which connects the discharge side of said pump to the reservir,a pressure controlling relief valve in said bypass passage, said drive shaft including an axially extending first passage therein which communicates with said supply passage, a cross opening in the portion of said drive shaft in said upper compartment, said cross opening extending diametrically across said drive shaft, an elongated tubular cross shaft in said upper compartment fixed in said cross opening in sealing relationship therewith, said cross shaft having a second passage therein, a first port in said cross shaft connecting said first and second passages, a second port in said cross shaft near one end thereof and opening into said upper compartment, a tubular valve slidable over said cross shaft adjacent said second port, said second port when open providing an effective means for preventing an increase of pressure of fluid in said supply passage below a predetermined speed, said valve being movable by centrifugal force radially of said cross shaft across said second port to close said second port and thereby increase the fluid in said supply passage to a pressure limited by said relief valve, and a temperature responsive control valve mounted in said housing in said supply passage in series with and at a point upstream from said speed responsive valve to form a restriction variable in accordance with the temperature of the fluid for compensating for the effect of the temperature of the fluid on its viscosity.

7. The hydraulic speed and temperature responsive control system defined in claim 6 in which a discharge passage is provided in said barrier to connect said upper compartment with said reservoir.

8. The hydraulic speed and temperature responsive control system defined in claim 7 in which said one end of the cross shaft is provided with an adjustable spring seat and resilient means are provided between said seat and said valve'for holding said valve away from said second port until the predetermined speed has been attained.

9. A hydraulic speed and temperature responsive throttle governing system interposed between a source of hydraulic pressure employing hydraulic fluid which has its viscosity variable in accordance with its temperature and a throttle controlling motor, comprising a speed and temperature responsive device including a hydraulic fluid supply passage, a bypass passage connected to said supply passage, a speed responsive valve in said bypass passage which forms a variable restriction in said bypass passage at speeds approaching governed speed, and temperature responsive means interconnected in said supply passage in series with said speed responsive valve operable to form a restriction variable in accordance with the temperature of the hydraulic fluid for maintaining the pressure of the fluid at a value independent of the effect of the temperature of the hydraulic fluid on its viscosity.

10. The hydraulic speed and temperature responsive throttle governing system defined in claim 9 wherein said temperature responsive means is located directly in said supply passage at a point upstream from said speed responsive valve.

11. The hydraulic speed and temperature responsive throttle governing system defined in claim 9 wherein a pressure metering orifice is located in said supply passage in series with the variable restriction of said speed responsive valve and with the variable restriction of said temperature responsive means.

12. The hydraulic speed and temperature responsive throttle governing system defined in claim 9 wherein a relief passage is connected to said supply passage, and a pressure controlling relief valve in said relief passage for preventing the fluid pressure from exceeding a predetermined maximum.

References Cited by the Examiner UNITED STATES PATENTS 1,566,995 12/25 Standerwick 137-20 1,713,833 5/29 Kochendorfer 137-486 2,323,997 7/43 Hughes 137-58 2,398,713 4/46 Martin 137-58 2,606,542 8/52 Wallace 123-103 2,664,868 1/54 Lautzenhiser 123-103 2,722,205 11/55 Lautzenhiser 123-103 2,736,305 2/56 Kennedy 123-103 2,895,500 7/59 Barnett 137-468 2,915,076 12/59 Teumer 137-20 2,966,170 12/60 Raulins 137-468 2,976,946 3/61 Denman et al. 137-58 3,039,480 6/62 Cramer et a1. 137-34 3,085,619 4/63 Penny 137-56 X FOREIGN PATENTS 137,532 6/50 Australia. 561,982 8/58 Canada.

ISADOR WEIL, Primary Examiner.

KARL J. ALBRECHT, RICHARD WILKINSON,

Examiners. 

9. A HYDRAULIC SPEED AND TEMPERATURE RESPONSIVE THROTTLE GOVERNING SYSTEM INTERPOSED BETWEEN A SOURCE OF HYDRAULIC PRESSURE EMPLOYING HYDRAULIC FLUID WHICH HAS ITS VISCOSITY VARIABLE IN ACCORDANCE WITH ITS TEMPERATURE AND A THROTTLE CONTROLLING MOTOR, COMPRISING A SPEED AND TEMPERATURE RESPONSIVE DEVICE INCLUDING A HYDRAULIC FLUID SUPPLY PASSAGE, A BYPASS PASSAGE CONNECTED TO SAID SUPPLY PASSAGE, A SPEED RESPONSIVE VALVE IN SAID BYPASS PASSAGE WHICH FORMS A VARIABLE RESTRICTION IN SAID BYPASS PASSAGE AT SPEEDS APPROACHING GOVERNED SPEED, AND TEMPERATURE RESPONSIVE MEANS INTERCONNECTED IN SAID SUPPLY PASSAGE IN SERIES WITH SAID SPEED RESPONSIVE VALVE OPERABLE TO FORM A RESTRICTION VARIABLE IN ACCORDANCE WITH THE TEMPERATURE OF THE HYDRAULIC FLUID FOR MAINTAINING THE PRESSURE OF THE FLUID AT A VALUE INDEPENDENT OF THE EFFECT OF THE TEMPERATURE OF THE HYDRAULIC FLUID ON ITS VISCOSITY. 